Vocabulary

earthquake- the shaking that comes from the movement of rock beneath the Earth's surface

stress- a force that acts on rock to change its shape or volume

shearing- force of stress that pushes a mass of rock into opposite directions.

tension- the force of stress that stretches rock until it becomes thinner in the middle

compression- a stress force that squeezes rock so that it breaks or folds

deformation- any change in shape or volume in the Earth's crust

fault- a break in the Earth's crust where slabs of Earth

strike- slip fault- a fault that has rocks that moves past each other sideways with some up or down motion

normal fault- a fault that is at an angle, so that one block of rock is at the top and the other is on the bottom of the fault

hanging wall- half of the fault that lies above

footwall- half of the fault that lies below

reverse fault- the same arrangement as a normal fault but the blocks move in opposite directions

fault block mountain- when a normal block lifts a block of rock

fold- bends in a rock that folds when compression shortens and thickens part of Earths crust

antcline- a fold in a rock that bends upward into an dome

syncline- a fold in a rock that bends downward in the middle to form a bowl

plateau- a large area of flat land, elevated high above sea level

Outline

T= Earth's crust in motion


1. Stress in the crust

• types of stress
  • shearing

• cause rock to break and slip apart
• tension

*
* pulls on crust, stretching rock so it becomes thinner in the middle

• Compression
  • squeezes rock until it folds or breaks

1. Kinds of faults

• fault
  • strike- slip fault
    • rocks slip past each other sideways with an up or down motion
  • normal fault
    • fault is at an angle, one block lies on top and the other lies below the fault
  • reverse fault
    • same structure as the normal fault, but blocks move opposite directions

1. Friction along faults
*

• friction is force that opposes the motion of one surface as it moves across another surface
• how rocks move along faults depends on its friction
  • friction low- rocks slide past each other without much sticking
  • friction moderate- sides of faults jam together
  • friction high- rocks lock together, don't move

1. Mountain building

• normal fault lifts rock, fault- block mountains for
• 
  
• m
  • when two plates move opposite, tension forms
    • tension makes normal faults
      • normal faults= parallel, rock lying between them goes upward
        • when rock slides down, valley forms
  • fault- block mountain ranges
    • Sierra Nevada of California
    • Great Basin

1. Mountains formed by folding

• plate movement causes rock to fold
  • folds= bends in rock
  • folds= form when compression shortens, thickens crust
    • collisions in plates= cause compression, folding

1. Anticlines and synclines

• made from compression in the crust
• 
  

*
** anticline

• upward folds in rock
• syncline
  • downward folds in rock
  • anticline examples
    • Black Hills
      • in South Dakota
      • Made 65 million years ago
  • syncline examples
    • Illinois Basin
      • 
        
      • stretches from Indiana to Illinois
      • filled with soil and rock

1. Plateaus

• large area of flat land above sea level
  • form when vertical faults push up large rock block
  • has many flat layers
  • is wider than is tall
• examples of plateaus
  • 
    
  • Colorado Plateau
    • in the "Four Corners" region
    • roughly circular area
    • 500 kilometers across
    • much of plateau above sea level

    • The three types of stress and their affects